Coaxial cable, also called coax, is one of the most common and basic cable arrangements used to carry electricity or signals. Coaxial cable has an inner electrical conductor covered by a layer of electronic insulator (dielectric), which is covered by an outer tubular electrically conducting shield.
One significant advantage of the coaxial design is that electric and magnetic fields are restricted inside the outer shield essentially without any leakage. In other words, external electric or magnetic fields are blocked from inducing interference to the signals propagating inside the cable. This peculiarity of coaxial cable makes it attractive for many applications such as electronic systems in aircraft and space stations, signal distribution of video or cable television, data connections of computers, etc. In one particular application, coaxial cable has been used as connector in a recent Robotic Refueling Mission (RRM) outside the international space station.
Supercapacitors, also known as electrochemical capacitors, have become popular energy storage devices in recent years. Compared to other energy storage devices such as batteries, supercapacitors have faster charge-discharge rates, higher power densities, and longer lifetimes. As a signature of their performance, safety, and reliability, supercapacitors have recently been employed in the emergency doors of Airbus A380. Manganese dioxide (MnO2) has been used as a promising electrochemically active electrode material due to its outstanding characteristics such as high theoretical specific capacitance (˜1,400 F·g−1), natural abundance, and environmental friendliness. However, the relatively poor electrical conductivity of MnO2 has become the main bottleneck keeping supercapacitors with MnO2 from achieving theoretical values.